A's first-round pick Sonny Gray was 6-9 with a 4.14 ERA in 26 starts at Double-A Midland last season. He ended the season in Triple-A with the Sacramento RiverCats.(USA TODAY IMAGES)

PHOENIX -- Grant Balfour turned some heads when he walked into the A's clubhouse this morning. After undergoing a lateral meniscectomy on his right knee on Thursday, he was on his feet and in good spirits.

"He walked in here like he never had surgery," A's manager Bob Melvin said. "I know he's got a smile on his face because the surgery went well. He's walking around and hopefully we're looking at the shorter end of the spectrum than the longer end."

Balfour can already bend his right leg and said he could throw without issue before the surgery. He remains hopeful that he will be ready to return in time for opening day. Melvin knows when Balfour gets his mind set on something it is hard to hold him back.

"You don't reel him in," Melvin said of his determined closer. "You just hope to contain him a bit."

Strong Impression

The A's 2011 first round pick Sonny Gray has thrown two bullpens in camp -- both times Melvin walked away impressed. Gray is throwing a two-seam fastball that sinks, a four-seam fastball that cuts, a hard curveball, a normal curveball and a change up. In his second big league camp, the skipper says he notices a lot of growth from the 23-year-old righty.

"I feel a lot more relaxed this spring training, a lot more confident." Gray said. "Being around guys that I know now, last year was my first big league camp in general. I feel a lot better knowing what to expect."

Gray says he draws inspiration from what Dan Straily and A.J. Griffin did last season, when they rocketed from Double-A all the way to the big leagues.

"It just shows you that if you do well and perform and work hard anything is possible in this organization," Gray said.

The 18th overall pick out of Vanderbilt has a big arm even though he has a slight build. Gray was 6-9 with a 4.14 ERA in 26 starts at Double-A Midland last season. He ended the season in Sacramento where he started one game, allowing four runs in four innings.

"The beginning of the season was a struggle," Gray said. "I was working on things that were kind of getting in my head. This year it's kind of just, 'Alright lets get out there and make pitches and see where that takes us."

It's working so far.

Nakajima fitting in:

This morning Hiro Nakajima walked past me on the way out of the A's clubhouse and I yelled, "'Sup, bro!?" at him. He turned, smiled and responded "'Sup, bro!?"

The bro-down wasn't as impromptu as you'd think. Infielder Andy Parrino has been teaching Nakajima funny American phrases. He also learned to say '"Sup, girl? Can I buy you a drink?"

The Japanese native worked on making throws from shortstop to first base on Friday. He made strong accurate throws. It remains to be seen how he will handle similar throws while off-balance in live action. He was a three-time gold glove award-winner in Japan.

After practice, hitting coach Chili Davis and Nakajima spent some time in the dugout talking. Davis spent 19 years in the majors and dropped some veteran knowledge.

Working overtime

A's outfielder Michael Taylor took grounders with the team's first baseman, then did outfield work, then spent even more time taking throws at first after practice ended.

"It's smart, and he's smart for doing it," Melvin said. "We don't have very many right-handed first basemen here and he recognizes that. He wants to try to fit in however he can."

#FreeLayla:

Scott Sizemore wasn't with the team on Friday because he is at the hospital with his wife Brooke, who is in labor. They are expected to welcome their first child Layla in the coming hours.